It means you failed to generate a correct profile : your settings or procedure seems to be wrong.
I just verify and do not have same problem.
How did you use displaycal? which settings/target?
I have removed all Dell aps like Intel Control panel and Dell primer color and AFTER did a calibration with X1rite software and calibrator for photos.
Btw I assume you are aware of the distinction between the color-managed programs which use the color profiles and non-CM programs which use the LUT.
I don't have a problem with DPC when it comes to it's basic functionality. It switches gamut (+ set related icc profile automatically), and color temp. But... there's not a bit of information available how the program works. Does it write to panel 3x3 matrix LUT? If it does then using X-Rite software will make color look much worse because i1Profiler will manipulate GPU LUT (8bit per channel). Why doing calibration using DPC Calibration Wizard doesn't overwrite any icc profiles in C:\Windows\System32\spool\drivers\color? Instead it creates new profiles in C:\ProgramData\Portrait Displays\Dell PremierColor\calibration with same names (e.g. HP1476_sRGB_6500.icm). In the same folder, DPC create a corresponding text file: SHP1476_sRGB_6500.txt. The thing is after calibration Windows will still use the old profile, created during DPC installation. You can check that using DisplayCAL-profile-info.exe from DisplayCAL/Argyll. It doesn't make any sens. I started to bother Dell about that since it's simply bizarre that they do not provide such important info in user manuals.
We have sent you an email with attachment which illustrates setup/usage of Dell Premier Color. Presently we do not have any online document to share the link. We have escalated this to our product group.
So this what I've got so far.
I have a question to everyone how advise removing DPC. How will you control gamut if you remove DPC?